Charles e



No Model.) C. E. SCRIBNBR.

DUPLEX ARG LAMP.

No. 512,401. Patented Jan. 9, 1894.

+ y 231/ ven/@ UNITED STATES PATENT OFFICE.

CHARLES E. SCRIBER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE XVESTERN ELECTRIC COMPANY, OE SAME PLACE.

DUPLEX ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 512,401, dated January 9, 1894.

Application led May 1, 1891. Renewed May 9,1893. Serial No. 473,603. (No model.)

To @ZZ whom it may con/cern.-

le it known that I, CHAELEs E. SOEIENEE, a citizen of the United States, residing at Chicago, 1n the county of Cook and State of Illinois, have invented a certain new and useful Improvementin Duplex Arc Lamps (Case No. 261,) of which the following is a full, clear, concise, and exact description, reference bein g had tothe accompanying drawings, form- Io ing a part of this specification.

My invention relates to duplex arc lamps; its object is to provide circuits and mechan- 1sm whereby two separate arc lamps connected to the same circuit may be caused to r 5 burn successively.

My invention comprises two arc lamps having separate and independent regulating mechanisms, connected one in a normally open and the other in a normally closed zo branch circuit between two supply mains, and

mechanism in that lamp situated in the normally open circuit which operates to close that circuit to form the arc between the carbons included in the circuit and to regulate z 5 the arc, when the resistance of the arc in the first lamp is slightly increased.

My invention may be generally described as follows: I provide in the normally closed branch circuit an ordinary single carbon arc 3o lamp, whose carbons are allowed to rest to gether when the lamp is idle; and in the normally open branch circuit, a special single "carbon lamp, whose carbons are maintained in separated relation when the lamp is idle,

3 5 by a spring which acts upon the regulating mechanism of the lamp, and holds the clutch clamped upon the carbon rod, and the carbons apart as stated. lVhen the lamps are in operation, however, this spring is opposed 4o in its action by an electro-magnet in shunt of the carbons of both lamps, which tends to cause an approach of the carbons of its lamp. A current entering the lamps, traverses that lamp whose circuit is complete; the magnets of the lamp are energized, the carbons are separated, and an arc forms and is regulated in the usual manner, until the carbons are consumed. Vhen the resistance of the arc becomes sufficient a current of such strength 5o passes through the electro-magnet of the second la'mp as to cause itto bring the carbons of that lamp together. The arc of the iirst lamp is shunted out; the electro-magnet of the second lamp also loses its current and allows the carbons to separate and form the second arc.. The regulating system now assumes a position of equilibrium in. which the effort of the spring to separate the carbons still further is balanced by the effort of the 'electro-magnet in shunt of the arc to bring 6o them together, and the arc of the second lamp is continually adjusted to a constant resistance.

My invention will be more clearly understood by reference to the accompanying draw- 6 5 ings, which is illustrative thereof.

In the drawings I have shown two arc lamps,

A and B, connected to supply mains in accordance with my invention. The lamp A at the left of the drawings is substantially the 7o same as that described in my Patent No. 415,571; I will therefore describe its construction but briefly.

An electro-magnet c included in circuit with the carbons of the lamp is adapted to act apon an armature d attached to a lever e pivoted to the lamp frame. A second electro-'magnetfof high resistance and connected in shunt of the carbons is adapted to act upon an armature g attached to a bell crank lever 8o h; this lever h is pivoted at its angle t' to the frame of the lamp. That arm of lever 7L which carries the armature g is furnished with lugs and a pivot 7e which serves as a fulcrum upon which rocking lever Z may turn. The longer arm of lever 7L is pressed toward the frame of the lamp by a spring m which thus acts to maintain armature g at a slight distance from the pole of magnet f. One end of rocking lever l is linked to the armature 9o lever e, and the other end to the lifting lever n. The lever n is pivoted at one end to the frame, and at the other end carries clutch o. Vertically through this clutch and adapted to be grasped by it, passes the carbon rod in which carries at its lower extremity the carbon q, one of the pair q q.

Referring now to the lamp B at the right of the drawing. An electro-magnet r connected in shunt of both pairs of carbons is adapted roo to act upon an armature s. The armature s is attached to a bell crank lever t pivoted at its angle a to the frame of the lamp B. That arm of the levert which carries the armature sis linked to the lifting lever u', which is pivoted at one end to the frame of the lamp, and carries at its other end the clutch o', through which passes the carbon rod p cariying carbon q', one of the pair q q. The downwardly projecting arm of lever t is pressed toward the frame of the lamp by spring o, with a force sufficient to lift the carbon and carbon rod, and maintain the carbons separated, when the electro-magnet o' is not exerting an abnormally great attraction upon its armature.

I will now proceed to describe the operation of two lamps so constructed and connected.

In t-heir idle condition,their mechanisms are in the positions shown. The carbons of lamp A rest together, completing the branch circuit through that lamp. The carbons of lamp B, on the contrary, are held separated, and consequentlythebranch circuitthroughthat lamp is not complete. A current entering from the positive main traverses the magnet c, carbon rod p, carbons q q, and reaches the negative main. The magnet c is energized bythe current through its coils, and it attracts its armature d; the motion of this armature is communicated through the system of levers e, Z, n, and their respective connecting links, and operates to litt clutch o; the clutch clamps upon the rod p, which, with its attached cai'- bon q, is raised, and an arc forms between the carbons q q. On account of the introduction of the resistance of the arc into the circuit, a portion of the current now flows through the shunt magnetf, causing it to attract its armature g; if the resistance of the arc is greater than a predetermined amount to which the lamp is adjusted, the armature g approaches the magnet f in opposition to the force of the spring m; the fnlcruin of rocking lever Z is thus lowered, and hence the clutch and upper carbon q, until equilibrium is established between the pressure of the spring m and the attraction of magnet f for its armature. When the clutch has been lowered until it comes into contact with the base of the lamp frame, its grasp upon the carbon rod p is relaxed slightly and the carbon rod slides down a slight distance, iminediately after which the former condition is resumed. This action of lamp A continues iintilthe carbons q q havebeen so far consumed that the head of the carbon rod p rests upon the top shown; the arc now slowly increases in length and resistance, until the strength of the current flowing through shunt magnet r of lamp B is such as to draw down its armature s in opposition to the pressure of springe until the carbons g q' are brought into contact. IVhen this occurs the arc between the carbons of the rst lamp is shunted out, and the shunt magnet r is at the same time deprived of its current. The force on the armature s being thus weakened, the carbons are again separated, and an arc is formed between them. At once the current is rsa-established through the shunt magnet r, and the regulating system assumes a position of equilibrium under the balanced forces of the attraction ot' the magnet 0 upon its armature, and the pressure of the spring o. Thereafter regulation of the length of the arc proceeds as described for the first lamp. It will be evident that the springe must exerta greater opposition to the attraction of the electromagnet r upon its armature than the spring m exerts in opposition to the attraction of the electro-magnetf for its armature, in order that any slight increase in the resistance of the arc at lamp A may not cause the lamp B to bring its carbons together. In consequence of this different adjustment, an arc at lamp B will be maintained of slightly greater length than at lamp A, but the difference between the two arcs may, with proper adJnstments of springs m and o, be made inappreciable.

It is obvious that any other single carbon lamp, whose carbons are allowed to rest in contact when the lamp is idle, could be substituted in my duplex lamp for the form of lamp shown; and, also, that various other arrangements of levers and clutches might be substituted tor those shown in the second burning or auxiliary lamp, without departing from the substance of my invention. Ilence I do not limit myself to the precise forms shown. g

Having thus clearly described my invention and its operation, I claim as new and desire to secuie by Letters Patentl. In a duplex arc lamp, the combination of a single carbon arc lamp whose carbons rest in contact when the lamp is idle, connected to supply mains, of a second arc lamp provided with mechanism adapted to maintain the carbons separated when the lamp is idle, and with an electro-magnet in shunt of the carbons of both lamps, which acts upon the said mechanism to cause the approach of the carbons toward each other when sulicient current passes through the electro magnet, substantially as and for the purpose specified.

2. In combination, an arc lamp having regulating mechanism which allows the carbons to remain in contact when the lamp is idle, connected between supply mains in a branch circuit which is normally closed through its carbons, and a second arc lamp having regulating mechanism which maintains its carbons separated wh en the lamp is idle, and provided with an electro-magnet in shunt of the carbons of both lamps, adapted to act upon the regulating mechanism to bring the carbons into contact when suicient current ilows through the electromagnet, connected to said supply mains in a second branch circuit which is normally open at the point of separation of the two carbons, substantially in the manner and for the purpose specified.

3. In combination, the arc lamp A connected between supply mains in abraneh circuit normally closed through the carbons of the lamp, and the lamp B connected between the same supply mains in a branch Circuit normally open at the point of separation of its carbone, provided With the spring o acting through levers to keep the oarbons separated, and with the electro-magnet r in shunt of the oarbons of both lamps, acting through levers to close the earbons togetherinoppositionto the spring e When sufficient current passes through the magnet r, su lostantially in the manner and for the purpose specified.

gized, and an electro-magnet in shunt of the oai-bons in the normally open eireuit adapted `to bring the earbons of that pair together whenitisenergized,substantiallyasdescribed. In Witness whereof I hereunto subscribe my name this 18th day of April, A. D. 1891.

CHARLES E. SCRIBNER.

Witnesses:

ELLA EDLER, GEORGE P. BARTON. 

